Speaking to THR, DeKnight confirms the existence of an singular “global plan” which runs through Jessica Jones, Luke Cage and Iron Fist, enroute to The Defenders — but rules out character cross-pollination in Daredevil:

There is an over-arching global plan culminating in The Defenders and some of that groundwork has been laid in Daredevil.

I’ve had people ask me if Jessica Jones or Luke Cage make an appearance in Daredevil this season and my answer is unfortunately no because we were operating pretty much in a vacuum with this first one.

Jessica Jones showrunner Melissa Rosenberg is adapting Bendis’ graphic novel. I was shooting the finale when Krysten Ritter was cast as Jessica Jones. With Daredevil being the first out of the gate, we didn’t have the opportunity to cross-pollinate with other shows because they still in their formative stages.

My hope is moving forward with Jessica Jones, Luke Cage and Iron Fist now we will see more cross-pollination. There is a global plan moving toward [event series] The Defenders. We started to put things in place.